Efficacy and safety outcomes of ultrasound assisted thrombolysis versus standard catheter direct thrombolysis in patients with submassive or massive pulmonary embolism: an updated meta-analysis

Background

The use of catheter-based thrombolysis in comparison to systemic thrombolytics has emerged as a potentially lifesaving therapy for patients with sub massive or massive pulmonary embolism (PE). The addition of ultrasound waves to accelerate lytic dispersion in ultrasound assisted thrombolysis (USAT) has been proposed to improve outcomes as compared to standard catheter-directed thrombolysis (SCDT). These two modalities have been compared in small studies, but larger population data on the outcomes of these therapies is still lacking.

Purpose

To assess the efficacy and safety of USAT versus SCDT in patients with submassive or massive pulmonary embolism.

Methods

A review of electronic databases (PubMed, Scopus, Embase, and Cochrane) was performed using keywords USAT, SCDT and PE and studies were included if efficacy and safety outcomes were compared between the two types of therapies. Efficacy outcomes that were evaluated included the reduction in right ventricle/left ventricle ratio (RV/LV ratio), pulmonary artery systolic pressure (PASP) and Miller score. Safety outcomes that were evaluated included major bleeding, mortality and length of ICU stay. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for continuous variables. Risk ratio (RR) and 95% CI were reported for dichotomous variables using the random effects model in comprehensive meta-analysis and RevMan 5.4.1 softwares.

Results

Six studies with a total of 381 patients (USAT n=204; SCDT n=177) were included. No statistical difference in efficacy outcomes of USAT over SCDT was noted in the degree of RV/LV ratio reduction (SMD: −0.507; CI: −1.386–0.373; p>0.05; I2=92%), PASP reduction (SMD: 0.037; CI: −0.404–0.478; p>0.05; I2=59%), or Miller score reduction (SMD: 0.303; CI: −0.481– 1.087; p>0.05; I2=82%). Safety outcomes were also not statistically different with similar rates of major bleeding (RR: 1.44; CI: 0.54–3.85; p>0.05; I2=4%), mortality (RR: 1.46; CI: 0.35–6.05; p>0.05; I2=0%) and length of ICU stay (SMD: −0.01; CI: −0.29–0.27; p>0.05; I2=31%) in both treatment groups.

Conclusion

Our data suggest that despite the technological advancement of USAT, there is no additional benefit over SCDT in terms of efficacy and safety. Further studies are warranted for both procedures investigating financial and clinical outcomes in real world practice.

Funding Acknowledgement

Type of funding sources: None.